1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2012, 2014 by Delphix. All rights reserved. 24 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 25 */ 26 27 #include <sys/zfs_context.h> 28 #include <sys/dbuf.h> 29 #include <sys/dnode.h> 30 #include <sys/dmu.h> 31 #include <sys/dmu_impl.h> 32 #include <sys/dmu_tx.h> 33 #include <sys/dmu_objset.h> 34 #include <sys/dsl_dir.h> 35 #include <sys/dsl_dataset.h> 36 #include <sys/spa.h> 37 #include <sys/zio.h> 38 #include <sys/dmu_zfetch.h> 39 #include <sys/range_tree.h> 40 41 static kmem_cache_t *dnode_cache; 42 /* 43 * Define DNODE_STATS to turn on statistic gathering. By default, it is only 44 * turned on when DEBUG is also defined. 45 */ 46 #ifdef DEBUG 47 #define DNODE_STATS 48 #endif /* DEBUG */ 49 50 #ifdef DNODE_STATS 51 #define DNODE_STAT_ADD(stat) ((stat)++) 52 #else 53 #define DNODE_STAT_ADD(stat) /* nothing */ 54 #endif /* DNODE_STATS */ 55 56 static dnode_phys_t dnode_phys_zero; 57 58 int zfs_default_bs = SPA_MINBLOCKSHIFT; 59 int zfs_default_ibs = DN_MAX_INDBLKSHIFT; 60 61 static kmem_cbrc_t dnode_move(void *, void *, size_t, void *); 62 63 static int 64 dbuf_compare(const void *x1, const void *x2) 65 { 66 const dmu_buf_impl_t *d1 = x1; 67 const dmu_buf_impl_t *d2 = x2; 68 69 if (d1->db_level < d2->db_level) { 70 return (-1); 71 } 72 if (d1->db_level > d2->db_level) { 73 return (1); 74 } 75 76 if (d1->db_blkid < d2->db_blkid) { 77 return (-1); 78 } 79 if (d1->db_blkid > d2->db_blkid) { 80 return (1); 81 } 82 83 if (d1->db_state == DB_SEARCH) { 84 ASSERT3S(d2->db_state, !=, DB_SEARCH); 85 return (-1); 86 } else if (d2->db_state == DB_SEARCH) { 87 ASSERT3S(d1->db_state, !=, DB_SEARCH); 88 return (1); 89 } 90 91 if ((uintptr_t)d1 < (uintptr_t)d2) { 92 return (-1); 93 } 94 if ((uintptr_t)d1 > (uintptr_t)d2) { 95 return (1); 96 } 97 return (0); 98 } 99 100 /* ARGSUSED */ 101 static int 102 dnode_cons(void *arg, void *unused, int kmflag) 103 { 104 dnode_t *dn = arg; 105 int i; 106 107 rw_init(&dn->dn_struct_rwlock, NULL, RW_DEFAULT, NULL); 108 mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL); 109 mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL); 110 cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL); 111 112 /* 113 * Every dbuf has a reference, and dropping a tracked reference is 114 * O(number of references), so don't track dn_holds. 115 */ 116 refcount_create_untracked(&dn->dn_holds); 117 refcount_create(&dn->dn_tx_holds); 118 list_link_init(&dn->dn_link); 119 120 bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr)); 121 bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels)); 122 bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift)); 123 bzero(&dn->dn_next_bonustype[0], sizeof (dn->dn_next_bonustype)); 124 bzero(&dn->dn_rm_spillblk[0], sizeof (dn->dn_rm_spillblk)); 125 bzero(&dn->dn_next_bonuslen[0], sizeof (dn->dn_next_bonuslen)); 126 bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz)); 127 128 for (i = 0; i < TXG_SIZE; i++) { 129 list_link_init(&dn->dn_dirty_link[i]); 130 dn->dn_free_ranges[i] = NULL; 131 list_create(&dn->dn_dirty_records[i], 132 sizeof (dbuf_dirty_record_t), 133 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 134 } 135 136 dn->dn_allocated_txg = 0; 137 dn->dn_free_txg = 0; 138 dn->dn_assigned_txg = 0; 139 dn->dn_dirtyctx = 0; 140 dn->dn_dirtyctx_firstset = NULL; 141 dn->dn_bonus = NULL; 142 dn->dn_have_spill = B_FALSE; 143 dn->dn_zio = NULL; 144 dn->dn_oldused = 0; 145 dn->dn_oldflags = 0; 146 dn->dn_olduid = 0; 147 dn->dn_oldgid = 0; 148 dn->dn_newuid = 0; 149 dn->dn_newgid = 0; 150 dn->dn_id_flags = 0; 151 152 dn->dn_dbufs_count = 0; 153 dn->dn_unlisted_l0_blkid = 0; 154 avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 155 offsetof(dmu_buf_impl_t, db_link)); 156 157 dn->dn_moved = 0; 158 return (0); 159 } 160 161 /* ARGSUSED */ 162 static void 163 dnode_dest(void *arg, void *unused) 164 { 165 int i; 166 dnode_t *dn = arg; 167 168 rw_destroy(&dn->dn_struct_rwlock); 169 mutex_destroy(&dn->dn_mtx); 170 mutex_destroy(&dn->dn_dbufs_mtx); 171 cv_destroy(&dn->dn_notxholds); 172 refcount_destroy(&dn->dn_holds); 173 refcount_destroy(&dn->dn_tx_holds); 174 ASSERT(!list_link_active(&dn->dn_link)); 175 176 for (i = 0; i < TXG_SIZE; i++) { 177 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 178 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 179 list_destroy(&dn->dn_dirty_records[i]); 180 ASSERT0(dn->dn_next_nblkptr[i]); 181 ASSERT0(dn->dn_next_nlevels[i]); 182 ASSERT0(dn->dn_next_indblkshift[i]); 183 ASSERT0(dn->dn_next_bonustype[i]); 184 ASSERT0(dn->dn_rm_spillblk[i]); 185 ASSERT0(dn->dn_next_bonuslen[i]); 186 ASSERT0(dn->dn_next_blksz[i]); 187 } 188 189 ASSERT0(dn->dn_allocated_txg); 190 ASSERT0(dn->dn_free_txg); 191 ASSERT0(dn->dn_assigned_txg); 192 ASSERT0(dn->dn_dirtyctx); 193 ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL); 194 ASSERT3P(dn->dn_bonus, ==, NULL); 195 ASSERT(!dn->dn_have_spill); 196 ASSERT3P(dn->dn_zio, ==, NULL); 197 ASSERT0(dn->dn_oldused); 198 ASSERT0(dn->dn_oldflags); 199 ASSERT0(dn->dn_olduid); 200 ASSERT0(dn->dn_oldgid); 201 ASSERT0(dn->dn_newuid); 202 ASSERT0(dn->dn_newgid); 203 ASSERT0(dn->dn_id_flags); 204 205 ASSERT0(dn->dn_dbufs_count); 206 ASSERT0(dn->dn_unlisted_l0_blkid); 207 avl_destroy(&dn->dn_dbufs); 208 } 209 210 void 211 dnode_init(void) 212 { 213 ASSERT(dnode_cache == NULL); 214 dnode_cache = kmem_cache_create("dnode_t", 215 sizeof (dnode_t), 216 0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0); 217 kmem_cache_set_move(dnode_cache, dnode_move); 218 } 219 220 void 221 dnode_fini(void) 222 { 223 kmem_cache_destroy(dnode_cache); 224 dnode_cache = NULL; 225 } 226 227 228 #ifdef ZFS_DEBUG 229 void 230 dnode_verify(dnode_t *dn) 231 { 232 int drop_struct_lock = FALSE; 233 234 ASSERT(dn->dn_phys); 235 ASSERT(dn->dn_objset); 236 ASSERT(dn->dn_handle->dnh_dnode == dn); 237 238 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 239 240 if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY)) 241 return; 242 243 if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { 244 rw_enter(&dn->dn_struct_rwlock, RW_READER); 245 drop_struct_lock = TRUE; 246 } 247 if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) { 248 int i; 249 ASSERT3U(dn->dn_indblkshift, >=, 0); 250 ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT); 251 if (dn->dn_datablkshift) { 252 ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT); 253 ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT); 254 ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz); 255 } 256 ASSERT3U(dn->dn_nlevels, <=, 30); 257 ASSERT(DMU_OT_IS_VALID(dn->dn_type)); 258 ASSERT3U(dn->dn_nblkptr, >=, 1); 259 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 260 ASSERT3U(dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 261 ASSERT3U(dn->dn_datablksz, ==, 262 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 263 ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0); 264 ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) + 265 dn->dn_bonuslen, <=, DN_MAX_BONUSLEN); 266 for (i = 0; i < TXG_SIZE; i++) { 267 ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels); 268 } 269 } 270 if (dn->dn_phys->dn_type != DMU_OT_NONE) 271 ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels); 272 ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL); 273 if (dn->dn_dbuf != NULL) { 274 ASSERT3P(dn->dn_phys, ==, 275 (dnode_phys_t *)dn->dn_dbuf->db.db_data + 276 (dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT))); 277 } 278 if (drop_struct_lock) 279 rw_exit(&dn->dn_struct_rwlock); 280 } 281 #endif 282 283 void 284 dnode_byteswap(dnode_phys_t *dnp) 285 { 286 uint64_t *buf64 = (void*)&dnp->dn_blkptr; 287 int i; 288 289 if (dnp->dn_type == DMU_OT_NONE) { 290 bzero(dnp, sizeof (dnode_phys_t)); 291 return; 292 } 293 294 dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec); 295 dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen); 296 dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid); 297 dnp->dn_used = BSWAP_64(dnp->dn_used); 298 299 /* 300 * dn_nblkptr is only one byte, so it's OK to read it in either 301 * byte order. We can't read dn_bouslen. 302 */ 303 ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT); 304 ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR); 305 for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++) 306 buf64[i] = BSWAP_64(buf64[i]); 307 308 /* 309 * OK to check dn_bonuslen for zero, because it won't matter if 310 * we have the wrong byte order. This is necessary because the 311 * dnode dnode is smaller than a regular dnode. 312 */ 313 if (dnp->dn_bonuslen != 0) { 314 /* 315 * Note that the bonus length calculated here may be 316 * longer than the actual bonus buffer. This is because 317 * we always put the bonus buffer after the last block 318 * pointer (instead of packing it against the end of the 319 * dnode buffer). 320 */ 321 int off = (dnp->dn_nblkptr-1) * sizeof (blkptr_t); 322 size_t len = DN_MAX_BONUSLEN - off; 323 ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype)); 324 dmu_object_byteswap_t byteswap = 325 DMU_OT_BYTESWAP(dnp->dn_bonustype); 326 dmu_ot_byteswap[byteswap].ob_func(dnp->dn_bonus + off, len); 327 } 328 329 /* Swap SPILL block if we have one */ 330 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) 331 byteswap_uint64_array(&dnp->dn_spill, sizeof (blkptr_t)); 332 333 } 334 335 void 336 dnode_buf_byteswap(void *vbuf, size_t size) 337 { 338 dnode_phys_t *buf = vbuf; 339 int i; 340 341 ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT)); 342 ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0); 343 344 size >>= DNODE_SHIFT; 345 for (i = 0; i < size; i++) { 346 dnode_byteswap(buf); 347 buf++; 348 } 349 } 350 351 void 352 dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx) 353 { 354 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 355 356 dnode_setdirty(dn, tx); 357 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 358 ASSERT3U(newsize, <=, DN_MAX_BONUSLEN - 359 (dn->dn_nblkptr-1) * sizeof (blkptr_t)); 360 dn->dn_bonuslen = newsize; 361 if (newsize == 0) 362 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN; 363 else 364 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 365 rw_exit(&dn->dn_struct_rwlock); 366 } 367 368 void 369 dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx) 370 { 371 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 372 dnode_setdirty(dn, tx); 373 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 374 dn->dn_bonustype = newtype; 375 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 376 rw_exit(&dn->dn_struct_rwlock); 377 } 378 379 void 380 dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx) 381 { 382 ASSERT3U(refcount_count(&dn->dn_holds), >=, 1); 383 ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); 384 dnode_setdirty(dn, tx); 385 dn->dn_rm_spillblk[tx->tx_txg&TXG_MASK] = DN_KILL_SPILLBLK; 386 dn->dn_have_spill = B_FALSE; 387 } 388 389 static void 390 dnode_setdblksz(dnode_t *dn, int size) 391 { 392 ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE)); 393 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 394 ASSERT3U(size, >=, SPA_MINBLOCKSIZE); 395 ASSERT3U(size >> SPA_MINBLOCKSHIFT, <, 396 1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8)); 397 dn->dn_datablksz = size; 398 dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT; 399 dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0; 400 } 401 402 static dnode_t * 403 dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db, 404 uint64_t object, dnode_handle_t *dnh) 405 { 406 dnode_t *dn; 407 408 dn = kmem_cache_alloc(dnode_cache, KM_SLEEP); 409 ASSERT(!POINTER_IS_VALID(dn->dn_objset)); 410 dn->dn_moved = 0; 411 412 /* 413 * Defer setting dn_objset until the dnode is ready to be a candidate 414 * for the dnode_move() callback. 415 */ 416 dn->dn_object = object; 417 dn->dn_dbuf = db; 418 dn->dn_handle = dnh; 419 dn->dn_phys = dnp; 420 421 if (dnp->dn_datablkszsec) { 422 dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT); 423 } else { 424 dn->dn_datablksz = 0; 425 dn->dn_datablkszsec = 0; 426 dn->dn_datablkshift = 0; 427 } 428 dn->dn_indblkshift = dnp->dn_indblkshift; 429 dn->dn_nlevels = dnp->dn_nlevels; 430 dn->dn_type = dnp->dn_type; 431 dn->dn_nblkptr = dnp->dn_nblkptr; 432 dn->dn_checksum = dnp->dn_checksum; 433 dn->dn_compress = dnp->dn_compress; 434 dn->dn_bonustype = dnp->dn_bonustype; 435 dn->dn_bonuslen = dnp->dn_bonuslen; 436 dn->dn_maxblkid = dnp->dn_maxblkid; 437 dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0); 438 dn->dn_id_flags = 0; 439 440 dmu_zfetch_init(&dn->dn_zfetch, dn); 441 442 ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type)); 443 444 mutex_enter(&os->os_lock); 445 if (dnh->dnh_dnode != NULL) { 446 /* Lost the allocation race. */ 447 mutex_exit(&os->os_lock); 448 kmem_cache_free(dnode_cache, dn); 449 return (dnh->dnh_dnode); 450 } 451 452 /* 453 * Exclude special dnodes from os_dnodes so an empty os_dnodes 454 * signifies that the special dnodes have no references from 455 * their children (the entries in os_dnodes). This allows 456 * dnode_destroy() to easily determine if the last child has 457 * been removed and then complete eviction of the objset. 458 */ 459 if (!DMU_OBJECT_IS_SPECIAL(object)) 460 list_insert_head(&os->os_dnodes, dn); 461 membar_producer(); 462 463 /* 464 * Everything else must be valid before assigning dn_objset 465 * makes the dnode eligible for dnode_move(). 466 */ 467 dn->dn_objset = os; 468 469 dnh->dnh_dnode = dn; 470 mutex_exit(&os->os_lock); 471 472 arc_space_consume(sizeof (dnode_t), ARC_SPACE_OTHER); 473 return (dn); 474 } 475 476 /* 477 * Caller must be holding the dnode handle, which is released upon return. 478 */ 479 static void 480 dnode_destroy(dnode_t *dn) 481 { 482 objset_t *os = dn->dn_objset; 483 boolean_t complete_os_eviction = B_FALSE; 484 485 ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0); 486 487 mutex_enter(&os->os_lock); 488 POINTER_INVALIDATE(&dn->dn_objset); 489 if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 490 list_remove(&os->os_dnodes, dn); 491 complete_os_eviction = 492 list_is_empty(&os->os_dnodes) && 493 list_link_active(&os->os_evicting_node); 494 } 495 mutex_exit(&os->os_lock); 496 497 /* the dnode can no longer move, so we can release the handle */ 498 zrl_remove(&dn->dn_handle->dnh_zrlock); 499 500 dn->dn_allocated_txg = 0; 501 dn->dn_free_txg = 0; 502 dn->dn_assigned_txg = 0; 503 504 dn->dn_dirtyctx = 0; 505 if (dn->dn_dirtyctx_firstset != NULL) { 506 kmem_free(dn->dn_dirtyctx_firstset, 1); 507 dn->dn_dirtyctx_firstset = NULL; 508 } 509 if (dn->dn_bonus != NULL) { 510 mutex_enter(&dn->dn_bonus->db_mtx); 511 dbuf_evict(dn->dn_bonus); 512 dn->dn_bonus = NULL; 513 } 514 dn->dn_zio = NULL; 515 516 dn->dn_have_spill = B_FALSE; 517 dn->dn_oldused = 0; 518 dn->dn_oldflags = 0; 519 dn->dn_olduid = 0; 520 dn->dn_oldgid = 0; 521 dn->dn_newuid = 0; 522 dn->dn_newgid = 0; 523 dn->dn_id_flags = 0; 524 dn->dn_unlisted_l0_blkid = 0; 525 526 dmu_zfetch_rele(&dn->dn_zfetch); 527 kmem_cache_free(dnode_cache, dn); 528 arc_space_return(sizeof (dnode_t), ARC_SPACE_OTHER); 529 530 if (complete_os_eviction) 531 dmu_objset_evict_done(os); 532 } 533 534 void 535 dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs, 536 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 537 { 538 int i; 539 540 ASSERT3U(blocksize, <=, 541 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 542 if (blocksize == 0) 543 blocksize = 1 << zfs_default_bs; 544 else 545 blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE); 546 547 if (ibs == 0) 548 ibs = zfs_default_ibs; 549 550 ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT); 551 552 dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d\n", dn->dn_objset, 553 dn->dn_object, tx->tx_txg, blocksize, ibs); 554 555 ASSERT(dn->dn_type == DMU_OT_NONE); 556 ASSERT(bcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)) == 0); 557 ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE); 558 ASSERT(ot != DMU_OT_NONE); 559 ASSERT(DMU_OT_IS_VALID(ot)); 560 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 561 (bonustype == DMU_OT_SA && bonuslen == 0) || 562 (bonustype != DMU_OT_NONE && bonuslen != 0)); 563 ASSERT(DMU_OT_IS_VALID(bonustype)); 564 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 565 ASSERT(dn->dn_type == DMU_OT_NONE); 566 ASSERT0(dn->dn_maxblkid); 567 ASSERT0(dn->dn_allocated_txg); 568 ASSERT0(dn->dn_assigned_txg); 569 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 570 ASSERT3U(refcount_count(&dn->dn_holds), <=, 1); 571 ASSERT(avl_is_empty(&dn->dn_dbufs)); 572 573 for (i = 0; i < TXG_SIZE; i++) { 574 ASSERT0(dn->dn_next_nblkptr[i]); 575 ASSERT0(dn->dn_next_nlevels[i]); 576 ASSERT0(dn->dn_next_indblkshift[i]); 577 ASSERT0(dn->dn_next_bonuslen[i]); 578 ASSERT0(dn->dn_next_bonustype[i]); 579 ASSERT0(dn->dn_rm_spillblk[i]); 580 ASSERT0(dn->dn_next_blksz[i]); 581 ASSERT(!list_link_active(&dn->dn_dirty_link[i])); 582 ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL); 583 ASSERT3P(dn->dn_free_ranges[i], ==, NULL); 584 } 585 586 dn->dn_type = ot; 587 dnode_setdblksz(dn, blocksize); 588 dn->dn_indblkshift = ibs; 589 dn->dn_nlevels = 1; 590 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 591 dn->dn_nblkptr = 1; 592 else 593 dn->dn_nblkptr = 1 + 594 ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 595 dn->dn_bonustype = bonustype; 596 dn->dn_bonuslen = bonuslen; 597 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 598 dn->dn_compress = ZIO_COMPRESS_INHERIT; 599 dn->dn_dirtyctx = 0; 600 601 dn->dn_free_txg = 0; 602 if (dn->dn_dirtyctx_firstset) { 603 kmem_free(dn->dn_dirtyctx_firstset, 1); 604 dn->dn_dirtyctx_firstset = NULL; 605 } 606 607 dn->dn_allocated_txg = tx->tx_txg; 608 dn->dn_id_flags = 0; 609 610 dnode_setdirty(dn, tx); 611 dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs; 612 dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen; 613 dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype; 614 dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz; 615 } 616 617 void 618 dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, 619 dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx) 620 { 621 int nblkptr; 622 623 ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE); 624 ASSERT3U(blocksize, <=, 625 spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 626 ASSERT0(blocksize % SPA_MINBLOCKSIZE); 627 ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); 628 ASSERT(tx->tx_txg != 0); 629 ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) || 630 (bonustype != DMU_OT_NONE && bonuslen != 0) || 631 (bonustype == DMU_OT_SA && bonuslen == 0)); 632 ASSERT(DMU_OT_IS_VALID(bonustype)); 633 ASSERT3U(bonuslen, <=, DN_MAX_BONUSLEN); 634 635 /* clean up any unreferenced dbufs */ 636 dnode_evict_dbufs(dn); 637 638 dn->dn_id_flags = 0; 639 640 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 641 dnode_setdirty(dn, tx); 642 if (dn->dn_datablksz != blocksize) { 643 /* change blocksize */ 644 ASSERT(dn->dn_maxblkid == 0 && 645 (BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) || 646 dnode_block_freed(dn, 0))); 647 dnode_setdblksz(dn, blocksize); 648 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = blocksize; 649 } 650 if (dn->dn_bonuslen != bonuslen) 651 dn->dn_next_bonuslen[tx->tx_txg&TXG_MASK] = bonuslen; 652 653 if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */ 654 nblkptr = 1; 655 else 656 nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT); 657 if (dn->dn_bonustype != bonustype) 658 dn->dn_next_bonustype[tx->tx_txg&TXG_MASK] = bonustype; 659 if (dn->dn_nblkptr != nblkptr) 660 dn->dn_next_nblkptr[tx->tx_txg&TXG_MASK] = nblkptr; 661 if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 662 dbuf_rm_spill(dn, tx); 663 dnode_rm_spill(dn, tx); 664 } 665 rw_exit(&dn->dn_struct_rwlock); 666 667 /* change type */ 668 dn->dn_type = ot; 669 670 /* change bonus size and type */ 671 mutex_enter(&dn->dn_mtx); 672 dn->dn_bonustype = bonustype; 673 dn->dn_bonuslen = bonuslen; 674 dn->dn_nblkptr = nblkptr; 675 dn->dn_checksum = ZIO_CHECKSUM_INHERIT; 676 dn->dn_compress = ZIO_COMPRESS_INHERIT; 677 ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR); 678 679 /* fix up the bonus db_size */ 680 if (dn->dn_bonus) { 681 dn->dn_bonus->db.db_size = 682 DN_MAX_BONUSLEN - (dn->dn_nblkptr-1) * sizeof (blkptr_t); 683 ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size); 684 } 685 686 dn->dn_allocated_txg = tx->tx_txg; 687 mutex_exit(&dn->dn_mtx); 688 } 689 690 #ifdef DNODE_STATS 691 static struct { 692 uint64_t dms_dnode_invalid; 693 uint64_t dms_dnode_recheck1; 694 uint64_t dms_dnode_recheck2; 695 uint64_t dms_dnode_special; 696 uint64_t dms_dnode_handle; 697 uint64_t dms_dnode_rwlock; 698 uint64_t dms_dnode_active; 699 } dnode_move_stats; 700 #endif /* DNODE_STATS */ 701 702 static void 703 dnode_move_impl(dnode_t *odn, dnode_t *ndn) 704 { 705 int i; 706 707 ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock)); 708 ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx)); 709 ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx)); 710 ASSERT(!RW_LOCK_HELD(&odn->dn_zfetch.zf_rwlock)); 711 712 /* Copy fields. */ 713 ndn->dn_objset = odn->dn_objset; 714 ndn->dn_object = odn->dn_object; 715 ndn->dn_dbuf = odn->dn_dbuf; 716 ndn->dn_handle = odn->dn_handle; 717 ndn->dn_phys = odn->dn_phys; 718 ndn->dn_type = odn->dn_type; 719 ndn->dn_bonuslen = odn->dn_bonuslen; 720 ndn->dn_bonustype = odn->dn_bonustype; 721 ndn->dn_nblkptr = odn->dn_nblkptr; 722 ndn->dn_checksum = odn->dn_checksum; 723 ndn->dn_compress = odn->dn_compress; 724 ndn->dn_nlevels = odn->dn_nlevels; 725 ndn->dn_indblkshift = odn->dn_indblkshift; 726 ndn->dn_datablkshift = odn->dn_datablkshift; 727 ndn->dn_datablkszsec = odn->dn_datablkszsec; 728 ndn->dn_datablksz = odn->dn_datablksz; 729 ndn->dn_maxblkid = odn->dn_maxblkid; 730 bcopy(&odn->dn_next_nblkptr[0], &ndn->dn_next_nblkptr[0], 731 sizeof (odn->dn_next_nblkptr)); 732 bcopy(&odn->dn_next_nlevels[0], &ndn->dn_next_nlevels[0], 733 sizeof (odn->dn_next_nlevels)); 734 bcopy(&odn->dn_next_indblkshift[0], &ndn->dn_next_indblkshift[0], 735 sizeof (odn->dn_next_indblkshift)); 736 bcopy(&odn->dn_next_bonustype[0], &ndn->dn_next_bonustype[0], 737 sizeof (odn->dn_next_bonustype)); 738 bcopy(&odn->dn_rm_spillblk[0], &ndn->dn_rm_spillblk[0], 739 sizeof (odn->dn_rm_spillblk)); 740 bcopy(&odn->dn_next_bonuslen[0], &ndn->dn_next_bonuslen[0], 741 sizeof (odn->dn_next_bonuslen)); 742 bcopy(&odn->dn_next_blksz[0], &ndn->dn_next_blksz[0], 743 sizeof (odn->dn_next_blksz)); 744 for (i = 0; i < TXG_SIZE; i++) { 745 list_move_tail(&ndn->dn_dirty_records[i], 746 &odn->dn_dirty_records[i]); 747 } 748 bcopy(&odn->dn_free_ranges[0], &ndn->dn_free_ranges[0], 749 sizeof (odn->dn_free_ranges)); 750 ndn->dn_allocated_txg = odn->dn_allocated_txg; 751 ndn->dn_free_txg = odn->dn_free_txg; 752 ndn->dn_assigned_txg = odn->dn_assigned_txg; 753 ndn->dn_dirtyctx = odn->dn_dirtyctx; 754 ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset; 755 ASSERT(refcount_count(&odn->dn_tx_holds) == 0); 756 refcount_transfer(&ndn->dn_holds, &odn->dn_holds); 757 ASSERT(avl_is_empty(&ndn->dn_dbufs)); 758 avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs); 759 ndn->dn_dbufs_count = odn->dn_dbufs_count; 760 ndn->dn_unlisted_l0_blkid = odn->dn_unlisted_l0_blkid; 761 ndn->dn_bonus = odn->dn_bonus; 762 ndn->dn_have_spill = odn->dn_have_spill; 763 ndn->dn_zio = odn->dn_zio; 764 ndn->dn_oldused = odn->dn_oldused; 765 ndn->dn_oldflags = odn->dn_oldflags; 766 ndn->dn_olduid = odn->dn_olduid; 767 ndn->dn_oldgid = odn->dn_oldgid; 768 ndn->dn_newuid = odn->dn_newuid; 769 ndn->dn_newgid = odn->dn_newgid; 770 ndn->dn_id_flags = odn->dn_id_flags; 771 dmu_zfetch_init(&ndn->dn_zfetch, NULL); 772 list_move_tail(&ndn->dn_zfetch.zf_stream, &odn->dn_zfetch.zf_stream); 773 ndn->dn_zfetch.zf_dnode = odn->dn_zfetch.zf_dnode; 774 ndn->dn_zfetch.zf_stream_cnt = odn->dn_zfetch.zf_stream_cnt; 775 ndn->dn_zfetch.zf_alloc_fail = odn->dn_zfetch.zf_alloc_fail; 776 777 /* 778 * Update back pointers. Updating the handle fixes the back pointer of 779 * every descendant dbuf as well as the bonus dbuf. 780 */ 781 ASSERT(ndn->dn_handle->dnh_dnode == odn); 782 ndn->dn_handle->dnh_dnode = ndn; 783 if (ndn->dn_zfetch.zf_dnode == odn) { 784 ndn->dn_zfetch.zf_dnode = ndn; 785 } 786 787 /* 788 * Invalidate the original dnode by clearing all of its back pointers. 789 */ 790 odn->dn_dbuf = NULL; 791 odn->dn_handle = NULL; 792 avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t), 793 offsetof(dmu_buf_impl_t, db_link)); 794 odn->dn_dbufs_count = 0; 795 odn->dn_unlisted_l0_blkid = 0; 796 odn->dn_bonus = NULL; 797 odn->dn_zfetch.zf_dnode = NULL; 798 799 /* 800 * Set the low bit of the objset pointer to ensure that dnode_move() 801 * recognizes the dnode as invalid in any subsequent callback. 802 */ 803 POINTER_INVALIDATE(&odn->dn_objset); 804 805 /* 806 * Satisfy the destructor. 807 */ 808 for (i = 0; i < TXG_SIZE; i++) { 809 list_create(&odn->dn_dirty_records[i], 810 sizeof (dbuf_dirty_record_t), 811 offsetof(dbuf_dirty_record_t, dr_dirty_node)); 812 odn->dn_free_ranges[i] = NULL; 813 odn->dn_next_nlevels[i] = 0; 814 odn->dn_next_indblkshift[i] = 0; 815 odn->dn_next_bonustype[i] = 0; 816 odn->dn_rm_spillblk[i] = 0; 817 odn->dn_next_bonuslen[i] = 0; 818 odn->dn_next_blksz[i] = 0; 819 } 820 odn->dn_allocated_txg = 0; 821 odn->dn_free_txg = 0; 822 odn->dn_assigned_txg = 0; 823 odn->dn_dirtyctx = 0; 824 odn->dn_dirtyctx_firstset = NULL; 825 odn->dn_have_spill = B_FALSE; 826 odn->dn_zio = NULL; 827 odn->dn_oldused = 0; 828 odn->dn_oldflags = 0; 829 odn->dn_olduid = 0; 830 odn->dn_oldgid = 0; 831 odn->dn_newuid = 0; 832 odn->dn_newgid = 0; 833 odn->dn_id_flags = 0; 834 835 /* 836 * Mark the dnode. 837 */ 838 ndn->dn_moved = 1; 839 odn->dn_moved = (uint8_t)-1; 840 } 841 842 #ifdef _KERNEL 843 /*ARGSUSED*/ 844 static kmem_cbrc_t 845 dnode_move(void *buf, void *newbuf, size_t size, void *arg) 846 { 847 dnode_t *odn = buf, *ndn = newbuf; 848 objset_t *os; 849 int64_t refcount; 850 uint32_t dbufs; 851 852 /* 853 * The dnode is on the objset's list of known dnodes if the objset 854 * pointer is valid. We set the low bit of the objset pointer when 855 * freeing the dnode to invalidate it, and the memory patterns written 856 * by kmem (baddcafe and deadbeef) set at least one of the two low bits. 857 * A newly created dnode sets the objset pointer last of all to indicate 858 * that the dnode is known and in a valid state to be moved by this 859 * function. 860 */ 861 os = odn->dn_objset; 862 if (!POINTER_IS_VALID(os)) { 863 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_invalid); 864 return (KMEM_CBRC_DONT_KNOW); 865 } 866 867 /* 868 * Ensure that the objset does not go away during the move. 869 */ 870 rw_enter(&os_lock, RW_WRITER); 871 if (os != odn->dn_objset) { 872 rw_exit(&os_lock); 873 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck1); 874 return (KMEM_CBRC_DONT_KNOW); 875 } 876 877 /* 878 * If the dnode is still valid, then so is the objset. We know that no 879 * valid objset can be freed while we hold os_lock, so we can safely 880 * ensure that the objset remains in use. 881 */ 882 mutex_enter(&os->os_lock); 883 884 /* 885 * Recheck the objset pointer in case the dnode was removed just before 886 * acquiring the lock. 887 */ 888 if (os != odn->dn_objset) { 889 mutex_exit(&os->os_lock); 890 rw_exit(&os_lock); 891 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_recheck2); 892 return (KMEM_CBRC_DONT_KNOW); 893 } 894 895 /* 896 * At this point we know that as long as we hold os->os_lock, the dnode 897 * cannot be freed and fields within the dnode can be safely accessed. 898 * The objset listing this dnode cannot go away as long as this dnode is 899 * on its list. 900 */ 901 rw_exit(&os_lock); 902 if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) { 903 mutex_exit(&os->os_lock); 904 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_special); 905 return (KMEM_CBRC_NO); 906 } 907 ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */ 908 909 /* 910 * Lock the dnode handle to prevent the dnode from obtaining any new 911 * holds. This also prevents the descendant dbufs and the bonus dbuf 912 * from accessing the dnode, so that we can discount their holds. The 913 * handle is safe to access because we know that while the dnode cannot 914 * go away, neither can its handle. Once we hold dnh_zrlock, we can 915 * safely move any dnode referenced only by dbufs. 916 */ 917 if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) { 918 mutex_exit(&os->os_lock); 919 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_handle); 920 return (KMEM_CBRC_LATER); 921 } 922 923 /* 924 * Ensure a consistent view of the dnode's holds and the dnode's dbufs. 925 * We need to guarantee that there is a hold for every dbuf in order to 926 * determine whether the dnode is actively referenced. Falsely matching 927 * a dbuf to an active hold would lead to an unsafe move. It's possible 928 * that a thread already having an active dnode hold is about to add a 929 * dbuf, and we can't compare hold and dbuf counts while the add is in 930 * progress. 931 */ 932 if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) { 933 zrl_exit(&odn->dn_handle->dnh_zrlock); 934 mutex_exit(&os->os_lock); 935 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_rwlock); 936 return (KMEM_CBRC_LATER); 937 } 938 939 /* 940 * A dbuf may be removed (evicted) without an active dnode hold. In that 941 * case, the dbuf count is decremented under the handle lock before the 942 * dbuf's hold is released. This order ensures that if we count the hold 943 * after the dbuf is removed but before its hold is released, we will 944 * treat the unmatched hold as active and exit safely. If we count the 945 * hold before the dbuf is removed, the hold is discounted, and the 946 * removal is blocked until the move completes. 947 */ 948 refcount = refcount_count(&odn->dn_holds); 949 ASSERT(refcount >= 0); 950 dbufs = odn->dn_dbufs_count; 951 952 /* We can't have more dbufs than dnode holds. */ 953 ASSERT3U(dbufs, <=, refcount); 954 DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount, 955 uint32_t, dbufs); 956 957 if (refcount > dbufs) { 958 rw_exit(&odn->dn_struct_rwlock); 959 zrl_exit(&odn->dn_handle->dnh_zrlock); 960 mutex_exit(&os->os_lock); 961 DNODE_STAT_ADD(dnode_move_stats.dms_dnode_active); 962 return (KMEM_CBRC_LATER); 963 } 964 965 rw_exit(&odn->dn_struct_rwlock); 966 967 /* 968 * At this point we know that anyone with a hold on the dnode is not 969 * actively referencing it. The dnode is known and in a valid state to 970 * move. We're holding the locks needed to execute the critical section. 971 */ 972 dnode_move_impl(odn, ndn); 973 974 list_link_replace(&odn->dn_link, &ndn->dn_link); 975 /* If the dnode was safe to move, the refcount cannot have changed. */ 976 ASSERT(refcount == refcount_count(&ndn->dn_holds)); 977 ASSERT(dbufs == ndn->dn_dbufs_count); 978 zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */ 979 mutex_exit(&os->os_lock); 980 981 return (KMEM_CBRC_YES); 982 } 983 #endif /* _KERNEL */ 984 985 void 986 dnode_special_close(dnode_handle_t *dnh) 987 { 988 dnode_t *dn = dnh->dnh_dnode; 989 990 /* 991 * Wait for final references to the dnode to clear. This can 992 * only happen if the arc is asyncronously evicting state that 993 * has a hold on this dnode while we are trying to evict this 994 * dnode. 995 */ 996 while (refcount_count(&dn->dn_holds) > 0) 997 delay(1); 998 ASSERT(dn->dn_dbuf == NULL || 999 dmu_buf_get_user(&dn->dn_dbuf->db) == NULL); 1000 zrl_add(&dnh->dnh_zrlock); 1001 dnode_destroy(dn); /* implicit zrl_remove() */ 1002 zrl_destroy(&dnh->dnh_zrlock); 1003 dnh->dnh_dnode = NULL; 1004 } 1005 1006 void 1007 dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object, 1008 dnode_handle_t *dnh) 1009 { 1010 dnode_t *dn; 1011 1012 dn = dnode_create(os, dnp, NULL, object, dnh); 1013 zrl_init(&dnh->dnh_zrlock); 1014 DNODE_VERIFY(dn); 1015 } 1016 1017 static void 1018 dnode_buf_pageout(void *dbu) 1019 { 1020 dnode_children_t *children_dnodes = dbu; 1021 int i; 1022 1023 for (i = 0; i < children_dnodes->dnc_count; i++) { 1024 dnode_handle_t *dnh = &children_dnodes->dnc_children[i]; 1025 dnode_t *dn; 1026 1027 /* 1028 * The dnode handle lock guards against the dnode moving to 1029 * another valid address, so there is no need here to guard 1030 * against changes to or from NULL. 1031 */ 1032 if (dnh->dnh_dnode == NULL) { 1033 zrl_destroy(&dnh->dnh_zrlock); 1034 continue; 1035 } 1036 1037 zrl_add(&dnh->dnh_zrlock); 1038 dn = dnh->dnh_dnode; 1039 /* 1040 * If there are holds on this dnode, then there should 1041 * be holds on the dnode's containing dbuf as well; thus 1042 * it wouldn't be eligible for eviction and this function 1043 * would not have been called. 1044 */ 1045 ASSERT(refcount_is_zero(&dn->dn_holds)); 1046 ASSERT(refcount_is_zero(&dn->dn_tx_holds)); 1047 1048 dnode_destroy(dn); /* implicit zrl_remove() */ 1049 zrl_destroy(&dnh->dnh_zrlock); 1050 dnh->dnh_dnode = NULL; 1051 } 1052 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1053 children_dnodes->dnc_count * sizeof (dnode_handle_t)); 1054 } 1055 1056 /* 1057 * errors: 1058 * EINVAL - invalid object number. 1059 * EIO - i/o error. 1060 * succeeds even for free dnodes. 1061 */ 1062 int 1063 dnode_hold_impl(objset_t *os, uint64_t object, int flag, 1064 void *tag, dnode_t **dnp) 1065 { 1066 int epb, idx, err; 1067 int drop_struct_lock = FALSE; 1068 int type; 1069 uint64_t blk; 1070 dnode_t *mdn, *dn; 1071 dmu_buf_impl_t *db; 1072 dnode_children_t *children_dnodes; 1073 dnode_handle_t *dnh; 1074 1075 /* 1076 * If you are holding the spa config lock as writer, you shouldn't 1077 * be asking the DMU to do *anything* unless it's the root pool 1078 * which may require us to read from the root filesystem while 1079 * holding some (not all) of the locks as writer. 1080 */ 1081 ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 || 1082 (spa_is_root(os->os_spa) && 1083 spa_config_held(os->os_spa, SCL_STATE, RW_WRITER))); 1084 1085 if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT) { 1086 dn = (object == DMU_USERUSED_OBJECT) ? 1087 DMU_USERUSED_DNODE(os) : DMU_GROUPUSED_DNODE(os); 1088 if (dn == NULL) 1089 return (SET_ERROR(ENOENT)); 1090 type = dn->dn_type; 1091 if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) 1092 return (SET_ERROR(ENOENT)); 1093 if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE) 1094 return (SET_ERROR(EEXIST)); 1095 DNODE_VERIFY(dn); 1096 (void) refcount_add(&dn->dn_holds, tag); 1097 *dnp = dn; 1098 return (0); 1099 } 1100 1101 if (object == 0 || object >= DN_MAX_OBJECT) 1102 return (SET_ERROR(EINVAL)); 1103 1104 mdn = DMU_META_DNODE(os); 1105 ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT); 1106 1107 DNODE_VERIFY(mdn); 1108 1109 if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) { 1110 rw_enter(&mdn->dn_struct_rwlock, RW_READER); 1111 drop_struct_lock = TRUE; 1112 } 1113 1114 blk = dbuf_whichblock(mdn, object * sizeof (dnode_phys_t)); 1115 1116 db = dbuf_hold(mdn, blk, FTAG); 1117 if (drop_struct_lock) 1118 rw_exit(&mdn->dn_struct_rwlock); 1119 if (db == NULL) 1120 return (SET_ERROR(EIO)); 1121 err = dbuf_read(db, NULL, DB_RF_CANFAIL); 1122 if (err) { 1123 dbuf_rele(db, FTAG); 1124 return (err); 1125 } 1126 1127 ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT); 1128 epb = db->db.db_size >> DNODE_SHIFT; 1129 1130 idx = object & (epb-1); 1131 1132 ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE); 1133 children_dnodes = dmu_buf_get_user(&db->db); 1134 if (children_dnodes == NULL) { 1135 int i; 1136 dnode_children_t *winner; 1137 children_dnodes = kmem_zalloc(sizeof (dnode_children_t) + 1138 epb * sizeof (dnode_handle_t), KM_SLEEP); 1139 children_dnodes->dnc_count = epb; 1140 dnh = &children_dnodes->dnc_children[0]; 1141 for (i = 0; i < epb; i++) { 1142 zrl_init(&dnh[i].dnh_zrlock); 1143 } 1144 dmu_buf_init_user(&children_dnodes->dnc_dbu, 1145 dnode_buf_pageout, NULL); 1146 winner = dmu_buf_set_user(&db->db, &children_dnodes->dnc_dbu); 1147 if (winner != NULL) { 1148 1149 for (i = 0; i < epb; i++) { 1150 zrl_destroy(&dnh[i].dnh_zrlock); 1151 } 1152 1153 kmem_free(children_dnodes, sizeof (dnode_children_t) + 1154 epb * sizeof (dnode_handle_t)); 1155 children_dnodes = winner; 1156 } 1157 } 1158 ASSERT(children_dnodes->dnc_count == epb); 1159 1160 dnh = &children_dnodes->dnc_children[idx]; 1161 zrl_add(&dnh->dnh_zrlock); 1162 dn = dnh->dnh_dnode; 1163 if (dn == NULL) { 1164 dnode_phys_t *phys = (dnode_phys_t *)db->db.db_data+idx; 1165 1166 dn = dnode_create(os, phys, db, object, dnh); 1167 } 1168 1169 mutex_enter(&dn->dn_mtx); 1170 type = dn->dn_type; 1171 if (dn->dn_free_txg || 1172 ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE) || 1173 ((flag & DNODE_MUST_BE_FREE) && 1174 (type != DMU_OT_NONE || !refcount_is_zero(&dn->dn_holds)))) { 1175 mutex_exit(&dn->dn_mtx); 1176 zrl_remove(&dnh->dnh_zrlock); 1177 dbuf_rele(db, FTAG); 1178 return (type == DMU_OT_NONE ? ENOENT : EEXIST); 1179 } 1180 if (refcount_add(&dn->dn_holds, tag) == 1) 1181 dbuf_add_ref(db, dnh); 1182 mutex_exit(&dn->dn_mtx); 1183 1184 /* Now we can rely on the hold to prevent the dnode from moving. */ 1185 zrl_remove(&dnh->dnh_zrlock); 1186 1187 DNODE_VERIFY(dn); 1188 ASSERT3P(dn->dn_dbuf, ==, db); 1189 ASSERT3U(dn->dn_object, ==, object); 1190 dbuf_rele(db, FTAG); 1191 1192 *dnp = dn; 1193 return (0); 1194 } 1195 1196 /* 1197 * Return held dnode if the object is allocated, NULL if not. 1198 */ 1199 int 1200 dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp) 1201 { 1202 return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, tag, dnp)); 1203 } 1204 1205 /* 1206 * Can only add a reference if there is already at least one 1207 * reference on the dnode. Returns FALSE if unable to add a 1208 * new reference. 1209 */ 1210 boolean_t 1211 dnode_add_ref(dnode_t *dn, void *tag) 1212 { 1213 mutex_enter(&dn->dn_mtx); 1214 if (refcount_is_zero(&dn->dn_holds)) { 1215 mutex_exit(&dn->dn_mtx); 1216 return (FALSE); 1217 } 1218 VERIFY(1 < refcount_add(&dn->dn_holds, tag)); 1219 mutex_exit(&dn->dn_mtx); 1220 return (TRUE); 1221 } 1222 1223 void 1224 dnode_rele(dnode_t *dn, void *tag) 1225 { 1226 uint64_t refs; 1227 /* Get while the hold prevents the dnode from moving. */ 1228 dmu_buf_impl_t *db = dn->dn_dbuf; 1229 dnode_handle_t *dnh = dn->dn_handle; 1230 1231 mutex_enter(&dn->dn_mtx); 1232 refs = refcount_remove(&dn->dn_holds, tag); 1233 mutex_exit(&dn->dn_mtx); 1234 1235 /* 1236 * It's unsafe to release the last hold on a dnode by dnode_rele() or 1237 * indirectly by dbuf_rele() while relying on the dnode handle to 1238 * prevent the dnode from moving, since releasing the last hold could 1239 * result in the dnode's parent dbuf evicting its dnode handles. For 1240 * that reason anyone calling dnode_rele() or dbuf_rele() without some 1241 * other direct or indirect hold on the dnode must first drop the dnode 1242 * handle. 1243 */ 1244 ASSERT(refs > 0 || dnh->dnh_zrlock.zr_owner != curthread); 1245 1246 /* NOTE: the DNODE_DNODE does not have a dn_dbuf */ 1247 if (refs == 0 && db != NULL) { 1248 /* 1249 * Another thread could add a hold to the dnode handle in 1250 * dnode_hold_impl() while holding the parent dbuf. Since the 1251 * hold on the parent dbuf prevents the handle from being 1252 * destroyed, the hold on the handle is OK. We can't yet assert 1253 * that the handle has zero references, but that will be 1254 * asserted anyway when the handle gets destroyed. 1255 */ 1256 dbuf_rele(db, dnh); 1257 } 1258 } 1259 1260 void 1261 dnode_setdirty(dnode_t *dn, dmu_tx_t *tx) 1262 { 1263 objset_t *os = dn->dn_objset; 1264 uint64_t txg = tx->tx_txg; 1265 1266 if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) { 1267 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1268 return; 1269 } 1270 1271 DNODE_VERIFY(dn); 1272 1273 #ifdef ZFS_DEBUG 1274 mutex_enter(&dn->dn_mtx); 1275 ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg); 1276 ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg); 1277 mutex_exit(&dn->dn_mtx); 1278 #endif 1279 1280 /* 1281 * Determine old uid/gid when necessary 1282 */ 1283 dmu_objset_userquota_get_ids(dn, B_TRUE, tx); 1284 1285 mutex_enter(&os->os_lock); 1286 1287 /* 1288 * If we are already marked dirty, we're done. 1289 */ 1290 if (list_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) { 1291 mutex_exit(&os->os_lock); 1292 return; 1293 } 1294 1295 ASSERT(!refcount_is_zero(&dn->dn_holds) || 1296 !avl_is_empty(&dn->dn_dbufs)); 1297 ASSERT(dn->dn_datablksz != 0); 1298 ASSERT0(dn->dn_next_bonuslen[txg&TXG_MASK]); 1299 ASSERT0(dn->dn_next_blksz[txg&TXG_MASK]); 1300 ASSERT0(dn->dn_next_bonustype[txg&TXG_MASK]); 1301 1302 dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n", 1303 dn->dn_object, txg); 1304 1305 if (dn->dn_free_txg > 0 && dn->dn_free_txg <= txg) { 1306 list_insert_tail(&os->os_free_dnodes[txg&TXG_MASK], dn); 1307 } else { 1308 list_insert_tail(&os->os_dirty_dnodes[txg&TXG_MASK], dn); 1309 } 1310 1311 mutex_exit(&os->os_lock); 1312 1313 /* 1314 * The dnode maintains a hold on its containing dbuf as 1315 * long as there are holds on it. Each instantiated child 1316 * dbuf maintains a hold on the dnode. When the last child 1317 * drops its hold, the dnode will drop its hold on the 1318 * containing dbuf. We add a "dirty hold" here so that the 1319 * dnode will hang around after we finish processing its 1320 * children. 1321 */ 1322 VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg)); 1323 1324 (void) dbuf_dirty(dn->dn_dbuf, tx); 1325 1326 dsl_dataset_dirty(os->os_dsl_dataset, tx); 1327 } 1328 1329 void 1330 dnode_free(dnode_t *dn, dmu_tx_t *tx) 1331 { 1332 int txgoff = tx->tx_txg & TXG_MASK; 1333 1334 dprintf("dn=%p txg=%llu\n", dn, tx->tx_txg); 1335 1336 /* we should be the only holder... hopefully */ 1337 /* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1); */ 1338 1339 mutex_enter(&dn->dn_mtx); 1340 if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) { 1341 mutex_exit(&dn->dn_mtx); 1342 return; 1343 } 1344 dn->dn_free_txg = tx->tx_txg; 1345 mutex_exit(&dn->dn_mtx); 1346 1347 /* 1348 * If the dnode is already dirty, it needs to be moved from 1349 * the dirty list to the free list. 1350 */ 1351 mutex_enter(&dn->dn_objset->os_lock); 1352 if (list_link_active(&dn->dn_dirty_link[txgoff])) { 1353 list_remove(&dn->dn_objset->os_dirty_dnodes[txgoff], dn); 1354 list_insert_tail(&dn->dn_objset->os_free_dnodes[txgoff], dn); 1355 mutex_exit(&dn->dn_objset->os_lock); 1356 } else { 1357 mutex_exit(&dn->dn_objset->os_lock); 1358 dnode_setdirty(dn, tx); 1359 } 1360 } 1361 1362 /* 1363 * Try to change the block size for the indicated dnode. This can only 1364 * succeed if there are no blocks allocated or dirty beyond first block 1365 */ 1366 int 1367 dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx) 1368 { 1369 dmu_buf_impl_t *db; 1370 int err; 1371 1372 ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset))); 1373 if (size == 0) 1374 size = SPA_MINBLOCKSIZE; 1375 else 1376 size = P2ROUNDUP(size, SPA_MINBLOCKSIZE); 1377 1378 if (ibs == dn->dn_indblkshift) 1379 ibs = 0; 1380 1381 if (size >> SPA_MINBLOCKSHIFT == dn->dn_datablkszsec && ibs == 0) 1382 return (0); 1383 1384 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1385 1386 /* Check for any allocated blocks beyond the first */ 1387 if (dn->dn_maxblkid != 0) 1388 goto fail; 1389 1390 mutex_enter(&dn->dn_dbufs_mtx); 1391 for (db = avl_first(&dn->dn_dbufs); db != NULL; 1392 db = AVL_NEXT(&dn->dn_dbufs, db)) { 1393 if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID && 1394 db->db_blkid != DMU_SPILL_BLKID) { 1395 mutex_exit(&dn->dn_dbufs_mtx); 1396 goto fail; 1397 } 1398 } 1399 mutex_exit(&dn->dn_dbufs_mtx); 1400 1401 if (ibs && dn->dn_nlevels != 1) 1402 goto fail; 1403 1404 /* resize the old block */ 1405 err = dbuf_hold_impl(dn, 0, 0, TRUE, FTAG, &db); 1406 if (err == 0) 1407 dbuf_new_size(db, size, tx); 1408 else if (err != ENOENT) 1409 goto fail; 1410 1411 dnode_setdblksz(dn, size); 1412 dnode_setdirty(dn, tx); 1413 dn->dn_next_blksz[tx->tx_txg&TXG_MASK] = size; 1414 if (ibs) { 1415 dn->dn_indblkshift = ibs; 1416 dn->dn_next_indblkshift[tx->tx_txg&TXG_MASK] = ibs; 1417 } 1418 /* rele after we have fixed the blocksize in the dnode */ 1419 if (db) 1420 dbuf_rele(db, FTAG); 1421 1422 rw_exit(&dn->dn_struct_rwlock); 1423 return (0); 1424 1425 fail: 1426 rw_exit(&dn->dn_struct_rwlock); 1427 return (SET_ERROR(ENOTSUP)); 1428 } 1429 1430 /* read-holding callers must not rely on the lock being continuously held */ 1431 void 1432 dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read) 1433 { 1434 uint64_t txgoff = tx->tx_txg & TXG_MASK; 1435 int epbs, new_nlevels; 1436 uint64_t sz; 1437 1438 ASSERT(blkid != DMU_BONUS_BLKID); 1439 1440 ASSERT(have_read ? 1441 RW_READ_HELD(&dn->dn_struct_rwlock) : 1442 RW_WRITE_HELD(&dn->dn_struct_rwlock)); 1443 1444 /* 1445 * if we have a read-lock, check to see if we need to do any work 1446 * before upgrading to a write-lock. 1447 */ 1448 if (have_read) { 1449 if (blkid <= dn->dn_maxblkid) 1450 return; 1451 1452 if (!rw_tryupgrade(&dn->dn_struct_rwlock)) { 1453 rw_exit(&dn->dn_struct_rwlock); 1454 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1455 } 1456 } 1457 1458 if (blkid <= dn->dn_maxblkid) 1459 goto out; 1460 1461 dn->dn_maxblkid = blkid; 1462 1463 /* 1464 * Compute the number of levels necessary to support the new maxblkid. 1465 */ 1466 new_nlevels = 1; 1467 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1468 for (sz = dn->dn_nblkptr; 1469 sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs) 1470 new_nlevels++; 1471 1472 if (new_nlevels > dn->dn_nlevels) { 1473 int old_nlevels = dn->dn_nlevels; 1474 dmu_buf_impl_t *db; 1475 list_t *list; 1476 dbuf_dirty_record_t *new, *dr, *dr_next; 1477 1478 dn->dn_nlevels = new_nlevels; 1479 1480 ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]); 1481 dn->dn_next_nlevels[txgoff] = new_nlevels; 1482 1483 /* dirty the left indirects */ 1484 db = dbuf_hold_level(dn, old_nlevels, 0, FTAG); 1485 ASSERT(db != NULL); 1486 new = dbuf_dirty(db, tx); 1487 dbuf_rele(db, FTAG); 1488 1489 /* transfer the dirty records to the new indirect */ 1490 mutex_enter(&dn->dn_mtx); 1491 mutex_enter(&new->dt.di.dr_mtx); 1492 list = &dn->dn_dirty_records[txgoff]; 1493 for (dr = list_head(list); dr; dr = dr_next) { 1494 dr_next = list_next(&dn->dn_dirty_records[txgoff], dr); 1495 if (dr->dr_dbuf->db_level != new_nlevels-1 && 1496 dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && 1497 dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { 1498 ASSERT(dr->dr_dbuf->db_level == old_nlevels-1); 1499 list_remove(&dn->dn_dirty_records[txgoff], dr); 1500 list_insert_tail(&new->dt.di.dr_children, dr); 1501 dr->dr_parent = new; 1502 } 1503 } 1504 mutex_exit(&new->dt.di.dr_mtx); 1505 mutex_exit(&dn->dn_mtx); 1506 } 1507 1508 out: 1509 if (have_read) 1510 rw_downgrade(&dn->dn_struct_rwlock); 1511 } 1512 1513 void 1514 dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx) 1515 { 1516 dmu_buf_impl_t *db; 1517 uint64_t blkoff, blkid, nblks; 1518 int blksz, blkshift, head, tail; 1519 int trunc = FALSE; 1520 int epbs; 1521 1522 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1523 blksz = dn->dn_datablksz; 1524 blkshift = dn->dn_datablkshift; 1525 epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 1526 1527 if (len == DMU_OBJECT_END) { 1528 len = UINT64_MAX - off; 1529 trunc = TRUE; 1530 } 1531 1532 /* 1533 * First, block align the region to free: 1534 */ 1535 if (ISP2(blksz)) { 1536 head = P2NPHASE(off, blksz); 1537 blkoff = P2PHASE(off, blksz); 1538 if ((off >> blkshift) > dn->dn_maxblkid) 1539 goto out; 1540 } else { 1541 ASSERT(dn->dn_maxblkid == 0); 1542 if (off == 0 && len >= blksz) { 1543 /* 1544 * Freeing the whole block; fast-track this request. 1545 * Note that we won't dirty any indirect blocks, 1546 * which is fine because we will be freeing the entire 1547 * file and thus all indirect blocks will be freed 1548 * by free_children(). 1549 */ 1550 blkid = 0; 1551 nblks = 1; 1552 goto done; 1553 } else if (off >= blksz) { 1554 /* Freeing past end-of-data */ 1555 goto out; 1556 } else { 1557 /* Freeing part of the block. */ 1558 head = blksz - off; 1559 ASSERT3U(head, >, 0); 1560 } 1561 blkoff = off; 1562 } 1563 /* zero out any partial block data at the start of the range */ 1564 if (head) { 1565 ASSERT3U(blkoff + head, ==, blksz); 1566 if (len < head) 1567 head = len; 1568 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off), TRUE, 1569 FTAG, &db) == 0) { 1570 caddr_t data; 1571 1572 /* don't dirty if it isn't on disk and isn't dirty */ 1573 if (db->db_last_dirty || 1574 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1575 rw_exit(&dn->dn_struct_rwlock); 1576 dmu_buf_will_dirty(&db->db, tx); 1577 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1578 data = db->db.db_data; 1579 bzero(data + blkoff, head); 1580 } 1581 dbuf_rele(db, FTAG); 1582 } 1583 off += head; 1584 len -= head; 1585 } 1586 1587 /* If the range was less than one block, we're done */ 1588 if (len == 0) 1589 goto out; 1590 1591 /* If the remaining range is past end of file, we're done */ 1592 if ((off >> blkshift) > dn->dn_maxblkid) 1593 goto out; 1594 1595 ASSERT(ISP2(blksz)); 1596 if (trunc) 1597 tail = 0; 1598 else 1599 tail = P2PHASE(len, blksz); 1600 1601 ASSERT0(P2PHASE(off, blksz)); 1602 /* zero out any partial block data at the end of the range */ 1603 if (tail) { 1604 if (len < tail) 1605 tail = len; 1606 if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, off+len), 1607 TRUE, FTAG, &db) == 0) { 1608 /* don't dirty if not on disk and not dirty */ 1609 if (db->db_last_dirty || 1610 (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) { 1611 rw_exit(&dn->dn_struct_rwlock); 1612 dmu_buf_will_dirty(&db->db, tx); 1613 rw_enter(&dn->dn_struct_rwlock, RW_WRITER); 1614 bzero(db->db.db_data, tail); 1615 } 1616 dbuf_rele(db, FTAG); 1617 } 1618 len -= tail; 1619 } 1620 1621 /* If the range did not include a full block, we are done */ 1622 if (len == 0) 1623 goto out; 1624 1625 ASSERT(IS_P2ALIGNED(off, blksz)); 1626 ASSERT(trunc || IS_P2ALIGNED(len, blksz)); 1627 blkid = off >> blkshift; 1628 nblks = len >> blkshift; 1629 if (trunc) 1630 nblks += 1; 1631 1632 /* 1633 * Dirty the first and last indirect blocks, as they (and/or their 1634 * parents) will need to be written out if they were only 1635 * partially freed. Interior indirect blocks will be themselves freed, 1636 * by free_children(), so they need not be dirtied. Note that these 1637 * interior blocks have already been prefetched by dmu_tx_hold_free(). 1638 */ 1639 if (dn->dn_nlevels > 1) { 1640 uint64_t first, last; 1641 1642 first = blkid >> epbs; 1643 if (db = dbuf_hold_level(dn, 1, first, FTAG)) { 1644 dmu_buf_will_dirty(&db->db, tx); 1645 dbuf_rele(db, FTAG); 1646 } 1647 if (trunc) 1648 last = dn->dn_maxblkid >> epbs; 1649 else 1650 last = (blkid + nblks - 1) >> epbs; 1651 if (last > first && (db = dbuf_hold_level(dn, 1, last, FTAG))) { 1652 dmu_buf_will_dirty(&db->db, tx); 1653 dbuf_rele(db, FTAG); 1654 } 1655 } 1656 1657 done: 1658 /* 1659 * Add this range to the dnode range list. 1660 * We will finish up this free operation in the syncing phase. 1661 */ 1662 mutex_enter(&dn->dn_mtx); 1663 int txgoff = tx->tx_txg & TXG_MASK; 1664 if (dn->dn_free_ranges[txgoff] == NULL) { 1665 dn->dn_free_ranges[txgoff] = 1666 range_tree_create(NULL, NULL, &dn->dn_mtx); 1667 } 1668 range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks); 1669 range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks); 1670 dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n", 1671 blkid, nblks, tx->tx_txg); 1672 mutex_exit(&dn->dn_mtx); 1673 1674 dbuf_free_range(dn, blkid, blkid + nblks - 1, tx); 1675 dnode_setdirty(dn, tx); 1676 out: 1677 1678 rw_exit(&dn->dn_struct_rwlock); 1679 } 1680 1681 static boolean_t 1682 dnode_spill_freed(dnode_t *dn) 1683 { 1684 int i; 1685 1686 mutex_enter(&dn->dn_mtx); 1687 for (i = 0; i < TXG_SIZE; i++) { 1688 if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK) 1689 break; 1690 } 1691 mutex_exit(&dn->dn_mtx); 1692 return (i < TXG_SIZE); 1693 } 1694 1695 /* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */ 1696 uint64_t 1697 dnode_block_freed(dnode_t *dn, uint64_t blkid) 1698 { 1699 void *dp = spa_get_dsl(dn->dn_objset->os_spa); 1700 int i; 1701 1702 if (blkid == DMU_BONUS_BLKID) 1703 return (FALSE); 1704 1705 /* 1706 * If we're in the process of opening the pool, dp will not be 1707 * set yet, but there shouldn't be anything dirty. 1708 */ 1709 if (dp == NULL) 1710 return (FALSE); 1711 1712 if (dn->dn_free_txg) 1713 return (TRUE); 1714 1715 if (blkid == DMU_SPILL_BLKID) 1716 return (dnode_spill_freed(dn)); 1717 1718 mutex_enter(&dn->dn_mtx); 1719 for (i = 0; i < TXG_SIZE; i++) { 1720 if (dn->dn_free_ranges[i] != NULL && 1721 range_tree_contains(dn->dn_free_ranges[i], blkid, 1)) 1722 break; 1723 } 1724 mutex_exit(&dn->dn_mtx); 1725 return (i < TXG_SIZE); 1726 } 1727 1728 /* call from syncing context when we actually write/free space for this dnode */ 1729 void 1730 dnode_diduse_space(dnode_t *dn, int64_t delta) 1731 { 1732 uint64_t space; 1733 dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n", 1734 dn, dn->dn_phys, 1735 (u_longlong_t)dn->dn_phys->dn_used, 1736 (longlong_t)delta); 1737 1738 mutex_enter(&dn->dn_mtx); 1739 space = DN_USED_BYTES(dn->dn_phys); 1740 if (delta > 0) { 1741 ASSERT3U(space + delta, >=, space); /* no overflow */ 1742 } else { 1743 ASSERT3U(space, >=, -delta); /* no underflow */ 1744 } 1745 space += delta; 1746 if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) { 1747 ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0); 1748 ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT)); 1749 dn->dn_phys->dn_used = space >> DEV_BSHIFT; 1750 } else { 1751 dn->dn_phys->dn_used = space; 1752 dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES; 1753 } 1754 mutex_exit(&dn->dn_mtx); 1755 } 1756 1757 /* 1758 * Call when we think we're going to write/free space in open context to track 1759 * the amount of memory in use by the currently open txg. 1760 */ 1761 void 1762 dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx) 1763 { 1764 objset_t *os = dn->dn_objset; 1765 dsl_dataset_t *ds = os->os_dsl_dataset; 1766 int64_t aspace = spa_get_asize(os->os_spa, space); 1767 1768 if (ds != NULL) { 1769 dsl_dir_willuse_space(ds->ds_dir, aspace, tx); 1770 dsl_pool_dirty_space(dmu_tx_pool(tx), space, tx); 1771 } 1772 1773 dmu_tx_willuse_space(tx, aspace); 1774 } 1775 1776 /* 1777 * Scans a block at the indicated "level" looking for a hole or data, 1778 * depending on 'flags'. 1779 * 1780 * If level > 0, then we are scanning an indirect block looking at its 1781 * pointers. If level == 0, then we are looking at a block of dnodes. 1782 * 1783 * If we don't find what we are looking for in the block, we return ESRCH. 1784 * Otherwise, return with *offset pointing to the beginning (if searching 1785 * forwards) or end (if searching backwards) of the range covered by the 1786 * block pointer we matched on (or dnode). 1787 * 1788 * The basic search algorithm used below by dnode_next_offset() is to 1789 * use this function to search up the block tree (widen the search) until 1790 * we find something (i.e., we don't return ESRCH) and then search back 1791 * down the tree (narrow the search) until we reach our original search 1792 * level. 1793 */ 1794 static int 1795 dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset, 1796 int lvl, uint64_t blkfill, uint64_t txg) 1797 { 1798 dmu_buf_impl_t *db = NULL; 1799 void *data = NULL; 1800 uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; 1801 uint64_t epb = 1ULL << epbs; 1802 uint64_t minfill, maxfill; 1803 boolean_t hole; 1804 int i, inc, error, span; 1805 1806 dprintf("probing object %llu offset %llx level %d of %u\n", 1807 dn->dn_object, *offset, lvl, dn->dn_phys->dn_nlevels); 1808 1809 hole = ((flags & DNODE_FIND_HOLE) != 0); 1810 inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1; 1811 ASSERT(txg == 0 || !hole); 1812 1813 if (lvl == dn->dn_phys->dn_nlevels) { 1814 error = 0; 1815 epb = dn->dn_phys->dn_nblkptr; 1816 data = dn->dn_phys->dn_blkptr; 1817 } else { 1818 uint64_t blkid = dbuf_whichblock(dn, *offset) >> (epbs * lvl); 1819 error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FTAG, &db); 1820 if (error) { 1821 if (error != ENOENT) 1822 return (error); 1823 if (hole) 1824 return (0); 1825 /* 1826 * This can only happen when we are searching up 1827 * the block tree for data. We don't really need to 1828 * adjust the offset, as we will just end up looking 1829 * at the pointer to this block in its parent, and its 1830 * going to be unallocated, so we will skip over it. 1831 */ 1832 return (SET_ERROR(ESRCH)); 1833 } 1834 error = dbuf_read(db, NULL, DB_RF_CANFAIL | DB_RF_HAVESTRUCT); 1835 if (error) { 1836 dbuf_rele(db, FTAG); 1837 return (error); 1838 } 1839 data = db->db.db_data; 1840 } 1841 1842 1843 if (db != NULL && txg != 0 && (db->db_blkptr == NULL || 1844 db->db_blkptr->blk_birth <= txg || 1845 BP_IS_HOLE(db->db_blkptr))) { 1846 /* 1847 * This can only happen when we are searching up the tree 1848 * and these conditions mean that we need to keep climbing. 1849 */ 1850 error = SET_ERROR(ESRCH); 1851 } else if (lvl == 0) { 1852 dnode_phys_t *dnp = data; 1853 span = DNODE_SHIFT; 1854 ASSERT(dn->dn_type == DMU_OT_DNODE); 1855 1856 for (i = (*offset >> span) & (blkfill - 1); 1857 i >= 0 && i < blkfill; i += inc) { 1858 if ((dnp[i].dn_type == DMU_OT_NONE) == hole) 1859 break; 1860 *offset += (1ULL << span) * inc; 1861 } 1862 if (i < 0 || i == blkfill) 1863 error = SET_ERROR(ESRCH); 1864 } else { 1865 blkptr_t *bp = data; 1866 uint64_t start = *offset; 1867 span = (lvl - 1) * epbs + dn->dn_datablkshift; 1868 minfill = 0; 1869 maxfill = blkfill << ((lvl - 1) * epbs); 1870 1871 if (hole) 1872 maxfill--; 1873 else 1874 minfill++; 1875 1876 *offset = *offset >> span; 1877 for (i = BF64_GET(*offset, 0, epbs); 1878 i >= 0 && i < epb; i += inc) { 1879 if (BP_GET_FILL(&bp[i]) >= minfill && 1880 BP_GET_FILL(&bp[i]) <= maxfill && 1881 (hole || bp[i].blk_birth > txg)) 1882 break; 1883 if (inc > 0 || *offset > 0) 1884 *offset += inc; 1885 } 1886 *offset = *offset << span; 1887 if (inc < 0) { 1888 /* traversing backwards; position offset at the end */ 1889 ASSERT3U(*offset, <=, start); 1890 *offset = MIN(*offset + (1ULL << span) - 1, start); 1891 } else if (*offset < start) { 1892 *offset = start; 1893 } 1894 if (i < 0 || i >= epb) 1895 error = SET_ERROR(ESRCH); 1896 } 1897 1898 if (db) 1899 dbuf_rele(db, FTAG); 1900 1901 return (error); 1902 } 1903 1904 /* 1905 * Find the next hole, data, or sparse region at or after *offset. 1906 * The value 'blkfill' tells us how many items we expect to find 1907 * in an L0 data block; this value is 1 for normal objects, 1908 * DNODES_PER_BLOCK for the meta dnode, and some fraction of 1909 * DNODES_PER_BLOCK when searching for sparse regions thereof. 1910 * 1911 * Examples: 1912 * 1913 * dnode_next_offset(dn, flags, offset, 1, 1, 0); 1914 * Finds the next/previous hole/data in a file. 1915 * Used in dmu_offset_next(). 1916 * 1917 * dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg); 1918 * Finds the next free/allocated dnode an objset's meta-dnode. 1919 * Only finds objects that have new contents since txg (ie. 1920 * bonus buffer changes and content removal are ignored). 1921 * Used in dmu_object_next(). 1922 * 1923 * dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0); 1924 * Finds the next L2 meta-dnode bp that's at most 1/4 full. 1925 * Used in dmu_object_alloc(). 1926 */ 1927 int 1928 dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset, 1929 int minlvl, uint64_t blkfill, uint64_t txg) 1930 { 1931 uint64_t initial_offset = *offset; 1932 int lvl, maxlvl; 1933 int error = 0; 1934 1935 if (!(flags & DNODE_FIND_HAVELOCK)) 1936 rw_enter(&dn->dn_struct_rwlock, RW_READER); 1937 1938 if (dn->dn_phys->dn_nlevels == 0) { 1939 error = SET_ERROR(ESRCH); 1940 goto out; 1941 } 1942 1943 if (dn->dn_datablkshift == 0) { 1944 if (*offset < dn->dn_datablksz) { 1945 if (flags & DNODE_FIND_HOLE) 1946 *offset = dn->dn_datablksz; 1947 } else { 1948 error = SET_ERROR(ESRCH); 1949 } 1950 goto out; 1951 } 1952 1953 maxlvl = dn->dn_phys->dn_nlevels; 1954 1955 for (lvl = minlvl; lvl <= maxlvl; lvl++) { 1956 error = dnode_next_offset_level(dn, 1957 flags, offset, lvl, blkfill, txg); 1958 if (error != ESRCH) 1959 break; 1960 } 1961 1962 while (error == 0 && --lvl >= minlvl) { 1963 error = dnode_next_offset_level(dn, 1964 flags, offset, lvl, blkfill, txg); 1965 } 1966 1967 /* 1968 * There's always a "virtual hole" at the end of the object, even 1969 * if all BP's which physically exist are non-holes. 1970 */ 1971 if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 && 1972 minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) { 1973 error = 0; 1974 } 1975 1976 if (error == 0 && (flags & DNODE_FIND_BACKWARDS ? 1977 initial_offset < *offset : initial_offset > *offset)) 1978 error = SET_ERROR(ESRCH); 1979 out: 1980 if (!(flags & DNODE_FIND_HAVELOCK)) 1981 rw_exit(&dn->dn_struct_rwlock); 1982 1983 return (error); 1984 } 1985